Looking for some new exhaust tips for my logs. How much HP would I be robbing my engine of if I stuck with 3in or would I be better off bumping up to 4in ?
The problem is not the outlets, but rather the log design.
Most logs have a limited ability to scavenge the other exhaust ports. This results in an undesirable pulse, I would imagine in some cases, the pressure drop across the tip (in this case inceasing the overall exhaust pressure) which could quite possibly increase actual power, maybe not at the very top end, but up to just short of wot.
This would mean running a larger impeller cut, keeping the rpm in check.
Just a hunch, never actually experimented with it.
I would doubt very seriously that a larger tip would make any difference at all other than being more obnoxious sound wise.
GT